Dyeing orlon type acrylic fibers



United States Patent 3,493,981 DYEING ORLON TYPE ACRYLIC FIBERS Masajiro Noda, Kiyoshi Shirasawa, Shizuo Nishino, and Shoji Takekoshi, Kyoto, Japan, assignors to Meisei Chemical Works, Ltd., Ukoto, Kyoto, Japan Filed Aug. 1, 1966, Ser. No. 569,354

Int. Cl. D06p 3/70 US. Cl. 8--172 10 Claims ABSTRACT OF THE DISCLOSURE The invention relates to the dyeing of acrylic fibers with a cationic dye and a carrier which is a cyanoethyl substituted aromatic compound The present invention relates to a method for the dyeing of Orlon type acrylic fibers, more particularly to a method for the dyeing of Orlon type acrylic fibers at low temperatures with cationic dyes in the presence of an aromatic compound as carrier.

Orlon type acrylic fibers as mentioned herein refer to acrylic fibers having acidic sites and dyeable with cationic dyes, and accordingly are distinguished from other type acrylic fibers such as those dyeable with acid dyes or dyeable with disperse dyes along. Orlon type acrylic fibers are now produced by various companies and sold in different trade names, respectively, such as Acrilan 16 (Chemstrand), Orlon (Du Pont Company), Toraylon (Toyo Rayon of Japan), Exlan D (Nippon Exlan Kogyo of Japan), Beslon (Toho Rayon of Japan) and Cash-milon F (Asahi Chemical of Japan). Cationic dyes herein refer to those which do not include SO H or OOOH- but can be rendered water-soluble by quinquevalent N atoms charged positive and by C1, SO H-, etc.

Conventionally, the fast color dyeing of Orlon type acrylic fibers with cationic dyes requires treatment in the dyebath for one to two hours at a high temperature in the neighborhood of 100 C. Although acrylic fibers have a high degree of molecular cohesive force at normal temperature, the movement of the high molecular chain is sharply increased at temperatures above the secondary transition point existing in the vicinity of 85 C. This results in typical activation diffusion, attended with an increase in the degree of permiation of the dyestuff ions, thus giving rise to rapid dyeing, so that uniform dyeing cannot be expected. In addition, those fibers have a nature such that as compared with polyamide type, polyester type fibers, etc., they tend to be easily shrunk and deformed in hot water and once deformed, they can never be restored to the original state, whatever physical or chemical treatment they may be subjected to, thus often detracting from the handling and external appearance of the dyeings.

In order to overcome such drawbacks, attempts have been made at dyeing acrylic fibers at lower temperatures, such as the neighborhood of 80 C. which are below their thermoplastic point. However, since acrylic fibers have a high degree of molecular cohesive force at temperatures below the secondary transistion point, the inter-fiber diffusion of dyestuff ions is insufficient, so that even if the fibers more or less absorb the dyestuff ions, their hue is different from that of usual boiled dyeings and their various fastness factors are still unsatisfactory.

In order to work out a solution to those problems, further researches have been conducted for a method in which a swelling agent, that is, the so-called carrier, which will not damage fibers, is added to the dyebath thereby to promote the dyeing.

It is well-known that materials having functional groups such as OH, NO:,, --Cl, CN and CH0 directly attached to aromatic nucleus are effective as carriers for the dyeing of acrylic fibers. Our researches and experiments, have however, shown that these compounds are hardly usuable in view of practical dyeing. Although the aromatic compounds having NO group are superior in carrier effect, when these substances, even if in very small amount, are retained in the fibers, the daylight-fastness of the dyeings is extremely lowered to such a degree that the dyeings cannot be put to practical use. The aromatic compounds having OH group are not sufiicient in carrier effect unless they are used in a relatively large amount. Of the latter compounds, particularly phenol having a relatively high degree of carrier effect is poisonous and dangerous in operation and handling in that, for example, it causes skin lesions. It is also known that compounds having C--CN group directly attached to the aromatic nucleus have a relatively good carrier effect. However, benzonitrile which is known as one having the highest effect among said compounds not only gives out a bad smell but also has a poisonous character, harmful to the human body. Phthalonitrile, isophthalodinitrile, a-naphthylcyanide, 3 naphthylcyanide, etc., though less badsmelling, are medium in the carrier effect and inadequate to use as a low temperature dyeing carrier for said object. Further, aromatic compounds having -C1 or CHO group are still insufficient in the carrier effect.

As a result of our various researches and experiments for a method of dying acrylic fibers at low temperatures below their thermoplastic points, it has been found and ascertained that aromatic compounds substituted by a cyanoethyl radical are less prominent in bad smell and poisonous character as giving rise to trouble in practical dyeing operation and where use is made of said compounds as carrier, at such low temperatures as below 50 C. where no occurrence of dyeing has heretofore been observed in the conventional dyeing methods, the dyeing really begins and proceeds gradually according to increase in the temperature wherein uniform dyeings are obtained as it is dyed while describing an ideal dyestuff absorbing curve by slow and suitable swelling action of said compounds and that in spite of low temperature dyeing at about C., the obtained dyeings are not less satisfactory in brilliancy, degree of exhaustion, and various fastness factors than usually boiled dyeings. Further, these dyeings are free from lowering in strength and elongation and subject to much less shrinkage and deformation than boiled dyeing there has thus been obtained a product which was never seen before, superior in external appearance and handling.

Aromatic compounds substituted by a cyanoethyl radical mentioned herein refer to those compounds expressed by the general formula,

wherein X represents hydrogen, lower alkyl or halogen, and Ar represents an aromatic group. The aromatic group has one, two or three rings, namely, it may be of any of benzene, naphthalene and anthracene nuclei. The aromatic group may have one-or two substituents of lower alkyl or halogen. Among such compounds as mentioned above there may be included directly cyanoethylated aromatic compounds as well as cyanoethylated substances of aromatic alcohol, aromatic amine and aromatic amide, for example, 01-O-omomon Qnnomcmcn CHzOOH2CHzCN [ID-minimums OITYCHZCHZCN S02NHCH2CHzCN The invention is, therefore, characterized in employing as carrier an aromatic compound substituted by a cyanoethyl radical in dyeing Orlon type acrylic fibers with cationic dyes, whereby in low temperature or short time dyeing operation there are obtained fast, brilliant and uniform dyeings high in color yield, without detracting from the handling and external appearance of the fibers.

The amount of aromatic compounds substituted by a cyanoethyl radical used in the process according to the invention may vary within Wide limits. When use is made of amount of 2 grams per liter of the dyebath, the effect on penetration is clearly visible. On the other hand, generally speaking, there are no advantages in using considerably more than grams of the aromatic compound per liter of the dyebath. From 1 to 10 grams per liter of the dyebath may, therefore, be regarded as the optimum range.

In carrying out the process according to the invention, a suitable emulsifying agent may also be used together with the above mentioned aromatic compounds as carrier. The emulsifying agent may be selected from 'per se known compounds but preferably is of the nonionic type. Polyethylene oxide condensed compounds are one of the most typical emulsifiers.

The temperature limits should be from 50 C. to 80 C., preferably 60 C. to 80 C. and most preferably 70 C. to 80 C. The time for the dyeing operation depends on the amount of the carrier, the bath ratio, the fibers to be dyed and the temperature of the dyebath, but generally it will be within the range 1 minute to 100 minutes, preferably 30 minutes to 60 minutes. The bath ratio may also be varied within wide limits, but practically it will be within the range of 1/2 to 1/100, preferably 1/ 10 to 1/50, most preferably around 1/40.

Cationic dyes used in the process according to the present invention are per se known compounds which are soluble in water.

In order to indicate still more fully the nature of the present invention, the following examples of typical procedure are set forth, it being understood however that this description is here presented by way of illustration only and not as limiting the scope of the invention.

EXAMPLE 1 A dyebath having a bath ratio of 50-fold is prepared which contains 2% of cationic dyestuff Sevron Blue 56 (C. I. Basic Blue 4) and 1% of glacial acetic acid with respect to 1,000 g. of high bulky yarn which is of Orlon type acrylic fibers Exlan D (trade name). Further, 30% of cyanoethyl benzyl ether is emulsified and dispersed in 2,000 cc. of hot water by the same amount of polypropylene glycol ethylene oxide addition product (nonionic surfactant). The emulsion is then poured into the dyebath. Subsequently, the yarn to be dyed is put into the dyebath, and while stirring the dyeing liquid, the temperature is raised and after the dyeing at 75 C. for one hour, soaping at a bath ratio of 50-fold at 70 C. for 10 to 20 minutes is carried out with a liquid of 0.5% Disper TL (a trade name for a condensate of naphthalene sulfonic acid and formaldehyde made by Meisei Chemical Ind. Co., Ltd. of Japan), followed by washing with water, squeezing and drying. As contrasted with the degree of exhaustion amounting only 40% when such carrier is not used, it is increased to as high as 95% when such carrier is used, the obtained dyeings being fast, uniform and brilliant and exceeding Class 4 of 118 (Japanese Industrial Standard) in colorfastness to each of light, washing, rubbing, perspiration and heat. The dyed yarn is free from lowering in strength and elongation, and uniformly and highly bulked; it is to be noted that as compared with a shrinkage factor of 22% which is usual with boiled dyeings processed by the conventional methods, such factor can be decreased to 16% in the present method, thus providing a highly elastic, tough dyed yarn. The dyed yarn may be treated with a solution containing a softening agent and oiling agent, followed by heat treatment with steam at 100 C. for 10 minutes, as in ordinary practice, whereby it is converted to a high bulky yarn having further improved restoration elasticity. It has been found that articles knitted with such yarn have superior handling and external appearance heretofore unattainable with the conventional boiled dyed yarn.

The accompanying drawing shows isothermal absorption curves at C. with respect to the above mentioned acrylic fiber Exlan D, wherein comparison is made between an instance in which the carrier according to the invention is used and a second instance in which it is not used. In the drawing, the reference letter (a) indicates an instance in which Du Pont Sevron Red (C.I. Basic Yellow 15) is used as a dyestuif with no addition of carrier; (b) an instance in which the same dyestuif as in (a) and carrier are used; (C) an instance in which Sevron Blue 4G (Du Pont) is used as the dyestuff with no addition of carrier; and (d) an instance in which the same carrier as in (c) and carrier are used. The dyeing conditions used are that 4% of dyestuff based on weight of fibers and 1 0 g./l. of carrier are used, with acetic acid added thereto to adjust the pH to 4, the dyeing thus being effected at a bath ratio of 1:50 at 80 C. The composition of the carrier is a mixture of cyanoethyl benzyl ether and fatty acid ethylene oxide addition product at a ratio of 1:1.

EXAMPLE 2 A dyebath having a bath ratio of 40-fold is prepared which contains 4% of cationic dyestuif, Sevron Brilliant Red 4G (C.I. Basic Red 14) and 1% of glacial acetic acid with respect to 1,000 g. of Orlon-type fiber Beslon White (trade name). 30% of cyanoethyl phenyl ether is emulsified and dispersed in 2000 cc. of hot water by the same amount of nonionic surfactant, fatty acid ethylene oxide addition product. The emulsion is then poured into the dyebath. Subsequently, an article to be dyed is put into the dyebath, the temperature is gradually raised and after the dyeing at 80% C. for 1 hour, soaping at a bath ratio of 40-fold at 70 C. for 10 to 20 .minutes is operated with a liquid of 0.5% Dethpar TL (a condensate product of a naphthalene sulfonic acid and formaldehyde made by Meisei Chem. Ind. Ltd. of Japan), followed by washing with water, squeezing and drying. Whereas the article is dyed only pale when not using the carrier, it can be dyed deep according to the present method. The dyed fabric was clear and beautiful. Thus, fast scarlet color exceeding Class 4 of I IS in colorfastness to each of light, heat, washing, rubbing and perspiration was obtained. The dyed fabric was almost free from creases, and even if they exist in small amounts, they could be easily removed by heat treatment with steam operated in the subsequent finishing process, the obtained product being superior in external appearance and handling.

The following table shows a comparison between the ordinary dyeings according to a conventional method and the low temperature dyeings according to the present invention, using Beslon White-type roving yarn, with respect to the degree of exhaustion and various fastness factors. In the table, boiling refers to an instance in which the conventional method without use of carrier is employed, and low temperature refers to an im stance in which dyeing is operated at low temperature by use of carrier according to the present invention. The condition for this low temperature dyeing is that 4% of dyestuff and g./ 1. of carrier a mixture of cyanoethyl benzyl ether and fatty acid ethylene oxide addition product at a ratio of 1:1) are used, acetic acid pH being 4, bath ratio being 1:50, the dyeing being operated at 80 C. for minutes. Further, the method of testing various fastness factors is in accordance with the following:

Color fastness to perspiration JIS L 0848, Method B. Color fastness to wet rubbing 115 L 1048, Gakushin type, 200 g. X 100 times. Color fastness to washing 118 L 1045, MC-3 (70 C.) Color fastness to light 118 L 1044, 40 hours. Color fastness to heat Dry (hot air) 150 C.

X 5 minutes; Wet (steam press) 120 C. x 10 minutes.

The measurement of the degree exhaustion is made with respect to the residual dyebath by using a photometer (Kotaki Seisakusho Model 5D).

said fibers with a cationic dye in the presence of a cyanoethyl substituted aromatic compound having the formula is a radical having one of the following structures:

Degree of Color tastness toexhaustion Dyestufi names Dyeing methods (percent) Perspiration Wet rubbing Washing Light Heat (wet) Heat (dry) Sevron Yellow 3RL (Du Boiling 95 5 4 5 5 4-5 4-5 Pont Low temperature 94 5 4-5 5 5 4-5 4-5 Sevron Orange (Du Pont)-- Boiling 94 5 4 4-5 5 5 4-5 Low temperature 95 4 4 4 5 5 5 Sevron Brilliant Red 4G Boiling 93 5 4 4-5 4 4 5 (Du Pont). Low temperature 95 5 4 4 4 4 5 Sevron Red GL (Du Pont)... Boiling 92 5 4 4 5 5 5 Low temperature- 93 5 4-5 4 5 5 5 Sevron Blue B (Du Pont) Boiling 95 5 4-5 4-5 5 4-5 4-5 Low temperature- 95 5 4-5 4-5 5 4-5 4-5 Sevron Blue 2G (Du Pont) Boiling 94 5 4-5 4-5 5 4-5 4-5 Low temperature 93 5 5 4-5 5 4-5 4-5 Sevron Blue 4G (Du Pent)... Boiling 94 5 4-5 4-5 5 4-5 4-5 Low temperature. 94 5 5 4-5 5 4-5 4-5 Sevron Green B (Du Pont) Boiling 92 5 4-5 4-5 5 4-5 4-5 Low temperature. 93 5 4-5 4-5 5 4-5 4-5 Astrazon Yellow 3G (B ayer) Boiling 94 5 4 5 5 4-5 4-5 Low temperatur 95 5 4-5 4-5 5 4-5 4-5 Astrazon Blue BG (Bayer) Boiling 96 4-5 4 4-5 5 4-5 4-5 Low temperature.-. 94 5 4-5 4-5 4 4-5 4-5 .Astrazon Blue 3RL (Bayer) Boiling 98 4-5 4 4-5 5 4-5 4-5 Low temperature. 97 5 5 5 5 4-5 4-5 Astrazon Black WRL Boiling 94 5 4 4 5 5 5 (Bayer). Low temperature 95 5 4-5 4 5 5 5 Basacryl Yellow 5GL Boiling 92 5 4-5 5 5 4-5 5 (BASF) Low temperatur 93 5 4-5 5 5 4-5 5 Basacryl Blue GL (BASF)... Boiling 93 4-5 4 4 5 4-5 5 Low temperature--- 96 5 4-5 4 5 4-5 4-5 Basacryl Blue 3RL (BASF) Boiling 95 4-5 4-5 4 5 4-5 5 Low temperature--- 92 5 4-5 4-5 5 4-5 5 In the foregoing table, dyestuffs therein listed correspond to the following Color Index (CI) numbers: C -CHz0-, Ha

CI Sevron Yellow 3RL (Du Pont) Basic Yellow 15. N 0 so N Sevron Orange G (Du Pont) Basic Orange 21. 0 Sevron Brilliant Red 4G (Du Pont) Basic Red 14. H N Sevron Red GL (Du Pont) Basic Red 18. Sevron Blue B (Du Pont) Basic Blue 21. SeVIOIl Blue 26 Pont) Basfc B1119 3. A method as in claim 1 wherein m is one or two. SfiVfOIl Green B P0111) Baslc Green 4. A method as in claim 1 wherein the aromatic com- Astfalon Yellow 3G y BaSlF Yellow pound is present in an amount of from about 1 to 10 Astrazon Blue BG (Bayer) Basic Blue 3. grams per liter of dye bath. AStfaZOIl Blue 3RL y l B1116 5. Acrylic fibers dyed in accordance with the process Basacryl Yellow 56L B2181}? Yellow of claim 1 in which the amount of dye is within the range Basacryl B1116 GL Blue of 2 to 4% by weight with respect tothe material to be Basacryl Blue 3RL (BASF) Baslc Blue 53. d d,

What we claim is: 1. A method of dyeing acrylic fibers having acidic sites and being dyeable by cationic dyes comprising treating 6. A method for imparting a fast color to acrylic fibers having acidic sites and being dyeable by cationic dyes comprising subjecting said fibers to treatment at a temperature within the range of about 50 to C. in aquex ous dyebath containing at least one cationic dye and a carrier, said carrier being a cyanoethyl substituted aromatic compound having the formula n is zero or one and m is zero, one or two, and removing dyed fibers from said dyebath, whereby the desired color is imparted throughout said fibers.

7. A method as in claim 6 wherein the temperature of treatment is at least about 60 C.

8. A method as in claim 7 wherein the aromatic compound is present in an amount of from about 1 to 10 grams per liter of dye bath.

9. Acrylic fibers dyed according to the process of claim 6 in which the amount of dye is Within the range of 2 to 4% by weight with respect to the material to be dyed.

10. A method as in claim 6 in which the carrier is further characterized as an addition product of acrylonitrile and an aromatic compound having an active hydrogen atom.

References Cited UNITED STATES PATENTS 4/1963 Hinton 8-55 3/1964 Fidell et a1. 855

US. Cl. X.R. 894, 177

mg? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,493,981 Dated February 10, 1970 Inventor) Masaj iro Neda, Kiyoshi Shirasawa, Shizuo Nishino and Shoji Takekoshi It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

zolunm 1, line 27, "along" should read alone line 66, .1

"those" should read these Column 2, line 17, after "having" delete "G"; line 48, "dyeing" should read dyeings Column 4, line 25, after "Red" insert GL In the table spanning columns 5 and 6, that portion in column 1 reading "Sevron Orange (Du Pont)" should read Sevron Orange G (Du Pont) Column 7, that portion of claim 6 reading Y is -CH 0, -0-, -S0 NH-, -NH-, or -c11 o-, -o-, -SO NH-, or -N- should read A Y is -CH O-, -0-, S0 NH-, -NH-, or -IiI- CH SIGNED AND SEALED JUN 3 01970 Q'S .Atteat:

M- Fle'det, E, I L Attesting Offioor (lomissioner of Pat ents J 

